Check out this thread:

http://www.xterraownersclub.com/cgi-local/ultimatebb.cgi?ubb=get_topic;f=4;t=002312

In shrot, it says that these lights need covers.
Is that the case in Arizona? My cursory reading of the ARS seems to indicate theya re just flat out not street legal--a problem for me since I have four of 'em on my roof!